1. Field of the Invention
The present invention is directed to a method and apparatus for continuously applying surface treatment onto an article such as a wire, rod, sheet or the like continuous material being fed along a pass line. More particularly, the invention is directed to cleaning off the water and scales remaining on an intermediate or final products of the above articles or coating a lubricant on the wire article prior to proceeding into a wire drawing process.
2. Description of the Prior Art
Such continuous articles are generally required to be subjected to a variety of surface treatments depending upon their applications. Included in these surface treatments are washing such as acid wash, alkaline wash, water wash, or wash with a detergent or a solution of trichloroethylene required prior to a plating operation or machining operation of forming the article into precision components which must be free from any dust or foreign matter, lubricant coating required prior to a wire drawing operation, coating the article in the form of a finished product with a rust-preventive oil, coating the article with paint powder for powder paining operation, and drying after the washing or before packing the final products. In all the cases, the entire surface of the article should h=treated without leaving any untreated portion irrespective of the cross sectional configuration of the article.
In the above wire drawing process, for example, there have been commonly employed a dry process in which the wire is coated with an emulsified lime and is then dried to form a dry coat of lime as a lubricant on the wire prior to being pulled through a draw plate, or a wet process in which the wire is pulled through a die of the draw plate while spraying a lubricant such as mineral oil, and a half-wet process in which the wire is finished with a wet coat of lime and is pulled through the draw plate before the coating is dried. The above processes, however, pose individual problems. That is, with the above dry process there is required a bothering and troublesome priming operation of firstly coating the emulsified lime and then drying the same, which renders this process rather inconvenient in addition to the fact that lime particles will be scattered around while the wire is pulled through the die to worsen a working environment.
Also with the above wet process, there should be additionally required a reservoir for recovering or circulating the lubricant used to be sprayed onto the drawing plate, limiting the process line solely to this process and not allowing the line to be applied to the other process. This also renders this process rather inconvenient in addition to the fact that the lubricant will be likewise scattered around to worsen the working environment.
Further with the half-wet process, the die suffers from considerable wearing while enabling a mirror-finished surface on the wire drawn, making the process rather inconvenient for practical use. As described, the individual processes involve their own limitations along with their advantages and require specific process lines which are not applicable to the other processes.
To this end, wire manufacturers are usually obliged to equip more than one of the process lines designed to the particular processes so as to be capable of performing the particular processes as required, which adds undue cost and is therefore disadvantageous from an economical view point.
Further, the wires employed in the drawing processes are not limited to have a circular cross section and may have other particular cross sections such as elliptical or polygonal cross sections or the cross sections with grooves or reccesses in its periphery. Such wires of differing cross section have been difficult to be successfully drawn by the use of one of the above processes. This also forces the wire manufactures to be equipped with more than one of the above process lines depending upon the differing cross sections of the wires being treated or equipped with other specially arranged lines suitable for particular cross section of the wires.
Additionally, since the above processes are normally performed in an open system the lubricants will spread around during the processing to thereby worsen the working environment.